It is well known that absorbent members are provided with a pressure sensitive adhesive layer in order to fix the absorbent member, for example a diaper or a sanitary napkin, to a piece of underwear. The diapers, pads or panty-liners are partly or fully coated with the above mentioned adhesive and usually provided with a silicon paper liner or siliconized plastic pouches to protect the pad adhesive during the manufacturing process, storage and transportation. Those liners are removed at the point of use.
The use of adhesive, however, has various disadvantages and drawbacks. Adhesive-based fastening systems, for instance, may leave residue on the wearer's clothes, may stick to the wearer's hair and skin, can be moisture sensitive, and can be difficult to reposition without losing adhesive strength and other characteristics. Adhesives can also cause the products to stick to themselves and/or to other adjacent products. For example, when these pads are used, the adhesive coated pads are often folded, twisted or bent, leading to an adhesive to adhesive contact which results in almost permanent destruction of the absorbent pads, even before the pad is ever used.
In another typical application for adult incontinence, the pads are not adhesive coated and rely on insertion of the absorbent pad into mesh pants, i.e. elasticized underwear substitutes. This solution is not satisfactory because of the problems with disorientation during use.
To overcome those problems at least partly, U.S. Pat. No. 5,415,650 B describes the possibility to provide a sanitary napkin as well as a piece of undergarment with a cohesive-adhesive. This application also recites to provide the sanitary napkin with side wings which can be folded around the undergarment to improve the fixation of the sanitary napkin and prevent it from disorientation during use.
In U.S. Pat. No. 6,358,234 B1, a sanitary napkin with elastic side-flaps is recited so that movements of the wearer of the sanitary napkin can be compensated better and a part of the mechanical stress may be removed from the adhesive bond area.
From U.S. Pat. No. 6,077,255 B it is known to fix sanitary napkins by a hook and loop system, in other words by purely mechanical fixation means. Such fastening systems typically include a male component that is configured to engage a female component. The male component typically includes a backing material with a number of protruding hook elements. In conventional hook and loop fastening systems, the female component comprises a backing member having a plurality of loops that are engaged by the hook elements. For example, in one embodiment, the hook element may include a base, a shank, and an engaging means in the form of a hook, a cap, a spherical/hemispherical shape, a flat top, etc. Recently, microprotrusions have been used as the male component of a hook and loop mechanical fastening system. The microprotrusions, for instance, have a length of less than about 0.9 cm, such as from about 0.1 cm to about 0.001 cm. Such microprotrusions are capable of engaging most textile materials, in addition to loop materials, without the need of a specially shaped engaging means located at the top of the protrusions.
Mechanical fastening systems including microprotrusions are particularly well suited for use in feminine hygiene products. Such protrusions, for instance, are capable of engaging a wearer's underwear for maintaining the product in the proper position. The underwear becomes the female component in the mechanical fastening system. Unfortunately, however, some of these mechanical fasteners can damage the underwear through unwanted engagement. For example, the female component can be damaged in various ways including but not limited to pilling, snagging, pull-out, abrasion, distortion, wear, residue, and the like. Pilling, for instance, is the tendency of woven fabrics and knits, especially wools, nylons, and acrylics, to form surface nubs or bunches of fibers. Pilling is caused by loosely twisted yarns and winding and interlocking with each other. Fiber pull-out is especially problematic. Fiber pull-out occurs when the male component pulls on and releases fibers from the female component. Even when a single engagement of a component of the mechanical fastener system might produce minimal damage to the underwear or other female component of the mechanical fastener system, multiple engagement of the male component might produce significant damage in the female component of the mechanical fastener system. This multiple engagement damage is especially important when one of the components is durable (not disposable), like underwear, and the other component is disposable, like a feminine hygiene product.
From U.S. Pat. No. 7,725,992 B2 it is known to modify at least a portion of the male component protrusions or microprotrusions to reduce female component damage like abrasion or fiber pull-out caused by the protrusions. The manner in which the protrusions are modified can vary depending upon the particular application and the desired result. The surface-modified mechanical fastener is well suited to being used on an absorbent article such as a diaper, a training pant, a feminine hygiene product, an incontinence product, a wound care product, a medical garment, and the like. When used in a feminine hygiene product, for instance, the mechanical fastener is capable of holding the product in position by attaching to a user's clothing without damaging the clothing during single or multiple engagements of the mechanical fastener system.
It is also known in the prior art to use several layers of sanitary napkins in the form of a stack so that during use the absorbent members are removed subsequently in top-down direction. Such a construction is described in US2005/0090792 A1.
This solution has the drawback that the sanitary product is overall quite thick, which reduces the wearing comfort. On the other hand, if each individual absorbent member is made very thin to compensate the problems of wearing comfort, the absorbent capabilities and thus the security is reduced as well.